From: Amp Set up Help

[SaxMan 2]

the sub sonic we use IF we put the sub in a ported box! IE if your box is tuned to 30hz we set the sub sonic to 30hz and we are good to go

the sub sonic cuts off the the frequencys that your box can't play

so basically i set the sub sonic to 33 Hz since that is what im planning on tuning the box to. and it will make it so the sub doesn't hit frequencies that will hurt it. right?